Decoding apparatus for error concealment considering motion directions of moving images

Abstract

A motion image decoding apparatus receives encoded image data which has first, second and third data regions, such as MPEG macroblocks which have predetermined sizes, and a motion vector for each of the data regions. The motion image decoding apparatus conceals errors in the first data region by generating an error signal and using a motion vector of a second data region which is located on a line preceding a line containing the first data region having the error and which is in a same picture as the first data region and also by using a motion vector corresponding to a third data region which is located in a column preceding the column containing the first data region having the error and which is also in a same picture as that of the first data region. If no error is generated in the first data region, the motion vector for that data region is used to perform motion compensation.

What is claimed is: 
     
       1. A motion image decoding apparatus which receives encoded image data of an image having a plurality of pictures, wherein the encoded image data has first, second and third data regions having predetermined sizes and which receives a motion vector for each of the data regions, comprising: decoding means for decoding the encoded image data and generating an error indication signal if an error is generated in image data of the first data region;   vector component generation means for generating and outputting first and second vector components, wherein said first and second vector components are generated from the motion vector corresponding to the first data region if said error indication signal indicates no error, and said first vector component is generated from the motion vector corresponding to the second data region which is located on a line preceding a line containing the first data region and which is in a same picture as the first data region and said second vector component is generated from the motion vector corresponding to the third data region which is located in a column preceding a column containing the first data region and which is in a same picture as that of the first data region, if said error indication signal indicates an error;   motion compensation means for compensating said image data of the first data region according to said first and second vector components output from said vector component generation means;   selection output means for outputting the decoded image data of the first data region decoded by said decoding means when said error indication signal indicates no error and outputting null data with respect to the first data region when said error indication signal indicates an error; and   adding means for adding the data output from said selection output means and decoded image data output from said motion compensation means.   
     
     
       2. The motion image decoding apparatus according to claim 1, wherein each of the data regions is a macroblock according to a data structure of the Moving Picture Experts Group (MPEG). 
     
     
       3. The motion image decoding apparatus according to claim 1, wherein said first vector component is a horizontal component of the motion vector and said second vector component is a vertical component of the motion vector. 
     
     
       4. The motion image decoding apparatus according to claim 1, wherein said first vector component is a vertical component of the motion vector and said second vector component is a horizontal component of the motion vector. 
     
     
       5. The motion image decoding apparatus according to claim 1, wherein said decoding means comprises a variable-length decoder which variable-length-decodes the encoded image data and generates said error indication signal based on said first data region of the variable-length-decoded image data. 
     
     
       6. The motion image decoding apparatus according to claim 1, wherein said second data region is located in an immediately preceding line of said first data region and in a same column as said first data region. 
     
     
       7. The motion image-decoding apparatus according to claim 1, wherein said third data region is located in an immediately preceding column of said first data region and in a same line as said first data region. 
     
     
       8. The motion image decoding apparatus according to claim 1, wherein said vector component generation means comprises: a component separator for separating the received motion vector into said first and second vector components;   a first delay for delaying said first vector component of the motion vector of the second data region output from said component separator to be synchronized with said first vector component of the motion vector of the first data region;   a first multiplexer for selectively outputting one of said first vector component of the motion vector of the first data region output from said component separator and said first vector component of the motion vector of the second data region output from said first delay, to said motion compensation means according to said error indication signal;   a second delay for delaying said second vector component of the motion vector of the third data region output from said component separator to be synchronized with said second vector component of the motion vector of the first data region; and   a second multiplexer for selectively outputting one of said second vector component of the motion vector of the first data region output from said component separator and said second vector component of the motion vector of the third data region output from said second delay, to said motion compensation means according to said error indication signal.   
     
     
       9. The motion image decoding apparatus according to claim 1, wherein said motion compensation means comprises: a frame memory for storing decoded image data fed back from said adding means; and   a motion compensator for outputting to said adding means image data in a data region from among said image data stored in said frame memory, corresponding to the motion vector composed of said first and second vector components output from said vector component generation means.   
     
     
       10. The motion image decoding apparatus according to claim 1, wherein said adding means feeds the added result back to said motion compensation means. 
     
     
       11. A motion image decoding apparatus which receives encoded image data of an image having a plurality of pictures, wherein the encoded image data has first, second and third data regions having predetermined sizes and which receives a motion vector for each of the data regions, comprising: a decoder which decodes the encoded image data and generates an error indication signal if an error is generated in image data of the first data region;   a vector component separator which receives said error indication signal from said decoder and the motion vector, in which said vector component separator generates and outputs first and second vector components, wherein said first and second vector components are generated from the motion vector corresponding to the first data region if said error indication signal indicates no error, and said first vector component is generated from the motion vector corresponding to the second data region which is located on a line preceding a line containing the first data region and which is in a same picture as the first data region and said second vector component is generated from the motion vector corresponding to the third data region which is located in a column preceding a column containing the first data region and which is in a same picture as that of the first data region, if said error indication signal indicates an error;   a motion compensator connected to said vector component separator, wherein said motion compensator compensates said image data of the first data region according to said first and second vector components output from said vector component separator;   a selector which receives said decoded image data of the first data region decoded by said decoder and said error indication signal, and selectively outputs said decoded image data of the first data region and null data based on said error indication signal; and   an adder receiving and adding the data selectively output from said selector and decoded image data output from said motion compensator.   
     
     
       12. The motion image decoding apparatus according to claim 11, wherein each of the data regions is a macroblock according to a data structure of the Moving Picture Experts Group (MPEG). 
     
     
       13. The motion image decoding apparatus according to claim 11, wherein said first vector component is a horizontal component of the motion vector and said second vector component is a vertical component of the motion vector. 
     
     
       14. The motion image decoding apparatus according to claim 11, wherein said first vector component is a vertical component of the motion vector and said second vector component is a horizontal component of the motion vector. 
     
     
       15. The motion image decoding apparatus according to claim 11, wherein said decoder is comprised of a variable-length decoder which variable-length-decodes the encoded image data and generates said error indication signal based on said first data region of the variable-length-decoded image data. 
     
     
       16. The motion image decoding apparatus according to claim 11, wherein said second data region is located in an immediately preceding line of said first data region and in a same column as said first data region. 
     
     
       17. The motion image-decoding apparatus according to claim 11, wherein said third data region is located in an immediately preceding column of said first data region and in a same line as said first data region. 
     
     
       18. The motion image decoding apparatus according to claim 11, wherein said vector component separator comprises: a component separator for separating the received motion vector into said first and second vector components;   a first delay for delaying said first vector component of the motion vector of the second data region output from said component separator to be synchronized with said first vector component of the motion vector of the first data region;   a first multiplexer for selectively outputting one of said first vector component of the motion vector of the first data region output from said component separator and said first vector component of the motion vector of the second data region output from said first delay, to said motion compensator according to said error indication signal;   a second delay for delaying said second vector component of the motion vector of the third data region output from said component separator to be synchronized with said second vector component of the motion vector of the first data region; and   a second multiplexer for selectively outputting one of said second vector component of the motion vector of the first data region output from said component separator and said second vector component of the motion vector of the third data region output from said second delay, to said motion compensator according to said error indication signal.   
     
     
       19. The motion image decoding apparatus according to claim 11, wherein said motion compensator comprises: a frame memory for storing decoded image data fed back from said adder; and   a motion compensation unit for outputting to said adder image data in a data region from among said image data stored in said frame memory, corresponding to the motion vector composed of said first and second vector components output from said vector component separator.   
     
     
       20. The motion image decoding apparatus according to claim 11, wherein said adder feeds the added result back to said motion compensator.